ESE's works engine tuner

[dinamik2t]

The single Ex port opened 78.5 deg ATDC @ 75% the tripple was going to be 85 but now its 82 @ 73%. The transfers are the same at 116-117-117, Inlet 145/85.

Nice!
In the tripple ex setup, perhaps you should rise the TFRs a little more.
And on a side note: in the sim, I always see a drop in power when Aux. Exs are at the same opening height as the main. I believe it's best to 'retard' them about 3-5 degrees.
RSA's auxiliaries must open after the main too - at least I reckon so from the photos. Frits or Wob could enlighten us when they have time.

[breezy]

Lots of interesting stuff there. Like running the piston back to front. I guess the ring ends travel on the portion of barrel between the transfers and exhaust port. How wide is the exhaust port? and it looks like its running an iron cylinder, BSA Bantam? also interesting combustion chamber shape too.

The motor does look like it has got hot.

Assuming you have the mixture and ignition timing correct and no air leaks then my money is on the inside diameter of the stinger (or stinger venturi) being to small, makes good power on the dyno but eventually over heats the motor and the piston crown in particular. How does the stinger size compare to other similarly setup engines.

Hopefully, some of the (more knowledgable than me) developers on here will post their ideas too.

heres a port map and exhaust diamentions and cylinder head insert. the ignition ducati energiser( kart ignition) mikuni 34mm flatslide. i did a leak test before pulling it a part at 6psi for 6mins and it was fine.i think the problem has been poor carb set up and probably ignition. the b10es plugs oiled up quickly at low revs looked to be slighty rich on inspection after a unexpected plug chop oppertunity!Attachment 262447Attachment 262448Attachment 262449

[TZ350]

An Email from Av's Dad.

Hi everyone, for those I haven't caught up with recently Avalon is
racing in Italy over the next six months in a five round Honda 600
series. This all came together very quickly and she left NZ asap to get
to a test day there. We have recently organised for her to also race the
same bike in the Italian Womens Championship to give her more track time
there.

WILsport management have come on board to assist us in making this
happen and a link to her latest report is below

http://wilsportsmanagement.com/latestnews.htm


Cheers
Keith

[TZ350]

How about a variable exhaust header. This one allows 25mm adjustment

Attachment 241299
Attachment 241300

Google translate says "a new control to include inflammation of RTD and the like" Thanks Google.

Kel reminded me of where he had posted pictures of a variable exhaust header.

[husaberg]

Kel reminded me of where he had posted pictures of a variable exhaust header.

Frits used the same example.

Bimota did that once: they built a pressurized thin-wall tubular frame with a manometer, so you could scientifically establish when the frame had developed a crack.
Added rigidity: sure. Maybe not so that you'd notice, but it certainly won't hurt. I once filled most cavities in my car with expanding building foam. It made the car feel twice as stiff!
Going electric on the movable pipes is not too bad either. I was talking about a Yam TZ500 four cylinder sidecar engine, but for a single the electricity consumption will not be all that much. Here are some pictures to wet your appetite:
Attachment 249693Attachment 249703Attachment 249694

It would certainly help with useful overrev on tight tracks as well as when you have a wide ratio gearbox


Variable pipe lengths with length or temps

You have to stay within certain length percentage limits for all elements of the exhaust system; you cannot make one part a lot longer or shorter in relation to the others without losing power somewhere.
It is best to concentrate on getting all dimensions correct for maximum power. In the high gears you don't ride low revs and in the low gears you'll have enough low-down power left to pull a wheelie or spin out the rear wheel (I'm not talking about buckets though, so you might want to reconsider your case).
If you have a decent setup for angle*areas, pipe, carburation and ignition, the necessary overrev potential will come naturally; no need to sacrifice maximum power in order to make it rev a little higher.

Re adjustable pipes
I know Cagiva ran a Hydraulic system and I think electric is to slow and to thirsty for power.
I also know that Cagiva ran the power valve (YAMAHA Style I guess) and Atac valve on the Randy Mamola bike.

Attachment 249692

I planed at a later stage to use a Greeves (woolley) style labryrinth seals with piston rings to seal the pipes.

My idea was compressed air. Easily rechargeable light nice and simple, super fast and a little goes along way.
I planed to run the Water injection the same way and use excess air in the pipes to reheat it them.
maybe a little fuel if there wasn't enough in the pipes to work it what do you think. I also envisaged using air/electric to trigger the Atac

Bimota did that once: they built a pressurized thin-wall tubular frame with a manometer, so you could scientifically establish when the frame had developed a crack.
Going electric on the movable pipes is not too bad either. I was talking about a Yam TZ500 four cylinder sidecar engine, but for a single the electricity consumption will not be all that much. Here are some pictures to wet your appetite:
Attachment 249693Attachment 249703Attachment 249694

How about a variable exhaust header. This one allows 25mm adjustment

Attachment 241299
Attachment 241300

Google translate says "a new control to include inflammation of RTD and the like" Thanks Google.

Compressed air is rechargeable and simple. I am not so sure about 'light and going a long way'. You might want to do a rough calculation on how much volume at what pressure you consume each time the pipe is moved. That could force you to use a bigger air bottle than you had planned...
A CO2-cartridge could be your way out: I estimate its energy density to be about a hundredfold better than air. Or, what I would do in Holland: use LPG (liquified petroleum gas, or autogas). I don't know whether you guys use the stuff in NZ, but I can get it at every street corner; the pressure is about 8 bar and being liquid its energy density (just talking about the pressure, not about what happens when you light it) is much better than that of compressed air.

Saving that for pulling the slippery pipe.

Frits Overmars

A powervalve does not really give you real resonance power; it just prevents the pipe pulses from completely messing up the power curve at low revs. I expect a sliding pipe will make more low-down power.

http://www.pit-lane.biz/t1666p15-tec...ht=twin+rotary

If you are using an Ignitech then by adding an RZ or R1 powervalve servo means you can program any position you like into a moving slide or rotary "timing changer" - easy.
Having a movable "slide" in behind the closing edge of a rotary valve, pushed/pulled into position by servo cables, would be easy and reliable. Get on with it.

I was just pointing out that the idea of using water, great as it may be in theory, and on a dyno when looking for bottom end, it "works" just fine.
But in a controlled test to see if its was useful, it failed, as the systems effect had to be reduced so much that any gain in bottom end was still offset by a loss in the top end.
As Burgess said, when the effect was useful, it took too long to reheat the pipes.
My thoughts, from the testing I did with a PV and ATAC operated separately ( instead of combined together as many MX engines have now) is that this works real well with no down sides at all,and is easy to implement.

OK, here is some info on how to utilise the servo option on the Ignitech.
The servo has 5 wires, two are 12V +/- and the other 3 are the servo feedback positioning pot.
Always wire the two functions on separate plugs. Once you have the servo connected to the blade or whatever, disconnect the servo motor power plug.
Then on the screen you will have a readout for the servo position, as mV or as a % if using the RACE box.
I have never used the % option so here is how to program the mV setup. Drive the servo to the travel limit ( in, or down or whatever) by gripping the servo wheel with vise grips.
Cycle it back and forth a few times to get an accurate position that takes up any small slack in the cables.
Note down the "servo measured" value on the screen. Then wind the servo around to the opposite limit, note this value down.
Then in the servo screen you can enter the two values of fully up, and fully down, with an rpm span between them.
Use a few of the extra points in between, so you can, if needed, force a non linear movement with rpm ie not a straight line.
Hit program, turn off the ECU, turn it on again, and it will cycle up and down,as it has been programmed.
You can check the up and down positions and compare the "servo measured" to the "servo desired" on screen, in real time.
The hysteresis should be set usually at around 100mV, less will speed up the response, but go too low and the servo will "hunt" around the values programmed.
The RZ servos are all getting old and shagged - the newer R1 servo is mechanically very similar but uses a special molded in plug - I have the right ones to match.
The R6 and ZXR ones are not as well made, the shaft isnt supported at both ends properly.
Here is a sample wiring setup and a PV curve, set to start opening at 7200 and full open at 9000, with about 1V of span between.
You could use this to rotate a spool like an RZ, a blade like a flat PV or even the 1/2 throttle plate if you wanted to.

Something to think about while the rest of the family occupy themselves with buying, boiling, painting, hiding, searching, finding and eating easter eggs: a couple of recent videos from the Dutch 50 cc scene.
http://www.youtube.com/watch?v=mvV4x...feature=relmfu
http://youtu.be/0odVzSgufjk

It was designed and built by Richard Maas http://www.adriaanmeeuwsen.nl/team-pagina.html. Hopefully we will see it in action next monday.
And if I were you, I would make it go shorter with rpm .

I'm impressed with how it slips all nice and steady!

Frits, may I ask, wouldn't it affect the 1st pressure wave in the diffuser, when fully inserted? -in a way to have a measurable impact on pipe effects I mean

You may. It will affect all the waves in the pipe. And it does have a measurable impact on pipe effects .
But I suspect you are referring to the header intruding into the diffuser. It doesn't. Even in the shortest position everything is smooth inside the pipe.

More news from Richard Maas. Did his trombone pipe give the desired results? O yes. At 10,000 rpm it gives 4 HP more than the same engine with a fixed pipe. It runs over 17,000 rpm without the need for a powerjet and with a fixed ignition timing. It is miles better than an engine with an exhaust power valve. And the mapping of pipe length, ignition timing and powerjet pulse width has yet to be carried out. Maybe the powerjet can disappear altogether.
Only problem so far: the piece of pipe that is fixed to the cylinder, is shrouded by the pipe that slides over it, so it gets very hot. Too hot for the Viton O-ring that is taking care of sealing. Any bright ideas, anyone?

I came upon this today.

Slippy exhaust pipes
Why they're so difficult to pull, and how to fix it...
There has recently been a thread on the Mailing List in regards to the amount of effort required to "pull" the typical slippy (adjustable) exhaust pipe that is common in many road racing classes.
Well... A bit over 20 years ago, I had the same frustration, and I'll explain what I found, and how I solved the problem.
The image below show's an approximation of a "typical" slippy exhaust pipe. I have not shown the outlet hole in the "can"... (and a number of other things are missing as well), but this will serve the purpose for now. The moveable rear (convergent) cone is shown in its "out" position by the blue lines... and in it's fully "in" position by the green lines. The thick magenta line is a rough representation of the cable which pulls the rear cone/stinger assembly.

OK... here's the problem in a nutshell: The amount of effort required to "pull" the rear cone is directly proportional to the difference in pressure between the front and back sides of the moveable cone. (There's some other minor things like friction, but they're insignificant compared to the pressure differential).
Since the the rear cone (at its big end) does not fit the large center section perfectly, some "pressure" leaks by the outside of the cone into the area behind the cone. If the outer rear cone (the one that supports the stinger) has too much clearance on the stinger (where I wrote "Here's the problem"), then the pressure behind the rear cone can "bleed" into the can (which has lower pressure than the inside of the exhaust pipe). This results in a pressure differential between the front (engine) side of the rear cone, and the back side.
THAT is what you are pulling "against" when you try to pull in your slippy pipe.

Now here's how I fixed the problem...
Years ago, Hartman Engineering made some very nice spun "outer" rear cones especially for slippy pipes. I started with one of those. They were made with a very large hole on the small end. (Oh... the other thing that was really nice about those Hartman cones is that they were very short. This allowed you to get the weld to the center section a long ways away from where the adjustable cone would be sliding.... which made it easier to keep the center section nice and round).
I made an insert for the small end of this cone (shown in red in the drawing below). This "insert" had a bit of a "bell-mouthed" shape to the inside diameter. I did this so that I could run a very tight fit to the stinger, without the stinger "binding" due to any misalignment that might exist. I also took the stinger material (before welding it to the cone) and had it hard-chromed, and then ground the outside diameter. This made it perfectly straight and round, as well as giving me a super fine finish that would resist any sort of galling or seizing. I gave the insert about .005 clearance on the stinger (as I recall).
How did it work?
Too well. At the time I was running Open class. Due to the power, Open engines were notorious for being almost impossible to pull the exhaust pipe for the full race (an hour long at the time). My first time on the track with this pipe was a complete surprise. The very first left-hand sweeper I went through, the rear cone went all the way in by itself, just from cornering force! The pipe was actually far too easy to pull. My solution was to experiment with "vent" holes into the can. With the clearance that I had given the stinger in my "support sleeve"... as well as the fit of the large end of the cone in the center section of the pipe... I ended up running a 3/16" diameter "bleed hole" from the outer rear cone (the short steep one in the drawing below) into the can. This gave just about the perfect "feel" in my case. I could operate the pipe handle with one finger... yet there was enough pressure on the cone to move it back out fairly quickly when I let go of the handle.

You may not care to build your own slippy pipe... and we're seeing less and less classes where slippys are allowed... but hopefully this might help some of you that still run them.
Just remember: the effort required to pull the rear cone is directly related to the pressure differential on the front and back sides of the moveable cone. Anything you can do to prevent leakage around the stinger and into the can will make the pipe easier to operate... up to the point (I discovered) where it's too easy.

There are several options in lengthening a pipe. You can move the end cone, like on the above drawing, or you can lengthen the header, like on the trombone pipe.
The gas pressure generates a force that is proportional to the cross section area of the moving part and proportional to the pressure difference at either side of that area. For a moving end cone this force can be up to 4 times larger than for a sliding header. That is one reason to go for the trombone system rather than the moving cone system.

The second reason: say you wish to lengthen the total length of the pipe by 10 %. If you do it by moving the end cone, you will also enlarge the pipe volume by a little over 10 %.
But in a good pipe configuration the header length is about 1/3 of total pipe length, so in the trombone system, lengthening the pipe by 10 % will result in lengthening the header by about 30 %. That gives a far greater variation in the pipe's Helmholtz frequency than a 10 % volume change.

It is true that the length percentages of all pipe components should be in a rather fixed relation to each other. Varying the lengths of all components by the same percentage would be the theoretical optimum, but that is not feasible.
Lengthening the belly will disturb the optimum relations, as will lengthening the header. So the pipe in its lengthened version will not be the optimum for the low resonance rpm dictated by the length. But it will be a hell of a lot better than using an exhaust power valve that spoils the 180° effective exhaust timing, necessary for true resonance.
And a pipe shortened beyond its optimum may not show the optimum length relations between its components either, but it will be a lot more effective in overrev than artificially raising the exhaust gas temperature by retarding the ignition, or by weakening the mixture strenght through closing a power jet, which has the disadvantage that not all inhaled air is used for combustion.

[TZ350]

130mm Trombone Header

After playing with EngMod2T for a bit I found that the interesting thing about the pipe elements needing to stay within certain percentage limits is that when you reduce the headers length, like in the Trombone arrangement the overall tuned length also reduces so the headers percentage of the overall length does not get out of balance as quickly as you might think.

[SS90]

heres a port map and exhaust diamentions and cylinder head insert. the ignition ducati energiser( kart ignition) mikuni 34mm flatslide. i did a leak test before pulling it a part at 6psi for 6mins and it was fine.i think the problem has been poor carb set up and probably ignition. the b10es plugs oiled up quickly at low revs looked to be slighty rich on inspection after a unexpected plug chop oppertunity!Attachment 262447Attachment 262448Attachment 262449

A B10 plug? Why is that? I have no experience with Bantams (other than my old man had one when he was a spotty yuoef), but even on a tuned up one it seems a bit cold...... There are plenty of Euro build air cooled smokers pumping out serious PS with hotter plugs than that. (I assume a Bantam is Piston ported going by your port map).... If so, there is easy power to be made judging by what you have posted. If you can bring your cylinder, head, cases, piston,ignition and exhaust to Waterloo in London sometime in the next two weeks I can liberate a few nags from the celler for nix. PM me if you like. (something like a working holiday)

[crazy man]

heres a port map and exhaust diamentions and cylinder head insert. the ignition ducati energiser( kart ignition) mikuni 34mm flatslide. i did a leak test before pulling it a part at 6psi for 6mins and it was fine.i think the problem has been poor carb set up and probably ignition. the b10es plugs oiled up quickly at low revs looked to be slighty rich on inspection after a unexpected plug chop oppertunity!Attachment 262447Attachment 262448Attachment 262449

do you know dr john here in nz . he is Bantam bad

[SwePatrick]

Hello guys..

I just have to say, a really really interesting thread.
took me 2 weeks to read it.(on sparetime at work)
And when i´m saying interesting i mean INTERESTING!!!!

Still taking i glimpse here and there to see if it has been updated.

I´m building a 'overkill' Honda MB5 here in Sweden and got much much good info here.

A preview pic:



Not complete at all on the pic,, but in progress.

[Yow Ling]

Hey Swepatrick, that looks pretty cool, what cylinder is it? Is there a race class for it?

[Yow Ling]

Did some messing round tonight , bored the cases to take a rz barrel. Dont have any idea if its clever or dumb yet, Monique can tell me
I have a bucket with a tf100 in it that I can test it in
.

[SwePatrick]

Hey Swepatrick, that looks pretty cool, what cylinder is it? Is there a race class for it?

Hello..

this bike isn´t for GP racing.. it´s for dragracing and topspeed events in Sweden for 'Mopeds'
It´s an old Kawasaki KX125 cylinder either -86 or -87.
I have bored it up to 58mm and with 49.5mm stroke(MT8 crank) it is now 136cc

A quick spec:

Kawasaki cylinder 58mm bore with woessnerpiston, new nicasil
'torus' combustionchamber 13-1 in ratio
V-force reeds
two carbs one 36mm and one 40mm(Mikuni TM/TMX)
Samarin CR125 rod, to get 1mm bigger wristpin and a little bit longer to fit better in cylinder, std is ~100mm now it´s 105mm, and finally bigger big end bearing.
Calculated exhaust(in progress right now)
6spd gearbox
Cylinder and exhaust tuned to get peak hp at ~12000rpm and ~1000rpm 'overrev'.

will build two models of clutch, one 8pcs and one 'slipclutch' with centrifugal weights.

the moped itself is an strengthened MB5 with uprated suspensions.
then lengthened and lowered to get some kind of good highspeed behaviour.

Rgds.
Patrick

[bucketracer]

Did some messing round tonight , bored the cases to take a rz barrel.

A reed valve cylinder on a rotary valve bottom end. Could the cylinder be turned so you could more easily fit a Trombone pipe and the reed valve cavity used for a variable crankcase volume or better yet fit an exciter to it that sends the case volume into resonance. 12,000rpm is only 200Hz, there must be all sorts of audio drivers that could be used.

[bucketracer]

Hello guys.
I´m building a 'overkill' Honda MB5 here in Sweden
Not complete, but in progress.

That's pretty interesting, any other pictures of moped sprinters?

[dinamik2t]

or better yet fit an exciter to it that sends the case volume into resonance. 12,000rpm is only 200Hz, there must be all sorts of audio drivers that could be used.

I 'm not sure whether this is the right way (one sample per cycle) to approach it. But anyway, sampling freq should be at least double the signal, ie >400Hz, to avoid anti-aliasing.
Nevertheless, audio cards support frequencies close to 100kHz, so..